# WAVES

## Two Types of Waves

Transverse and Longitudinal

## Transverse Waves

Definition: A wave where the motion of the particles in the medium is perpendicular to the wave's direction.

How they are created: Suppose that a slinky is stretched out and a pulse is introduced into the slinky on the left end by vibrating the first coil up and down. Energy will begin to be transport through the slinky from left to right. As the energy is transported from left to right, the individual coils of the medium will be displaced upwards and downwards. In this case, the particles of the medium move perpendicular to the direction that the pulse moves. Therefore, this creates a transverse wave.

Important in everyday life: They are used for many things that we use everyday. They can be light waves, radio waves, microwaves, television waves, and more. These allow all of us to see light, listen to the radio and watch tv.

## Longitudinal Waves

Definition: A wave where the medium is parallel to the wave's direction.

How they are created: As one particle is disturbed, it transmits the disturbance to the next particle. This continues to be passed and the result is that energy is transported from one end of the medium to the other end of the medium without the actual transport of matter.

Important in everyday life: We see longitudinal waves the most through sound waves. This allows us to hear all types of sounds.

## Spherical Waves

A wave whose surfaces form concentric spheres. The direction of travel is always perpendicular to the surfaces of the spheres.

## Plane Waves

A wave which has parallel rays. As an example, light waves from stars are plane waves when it hits a telescope lens.

## Dual Pin Interference

Definition: Interference of two sets of waves that have the same frequency. It creates a pattern of crests and troughs that intersect.

Constructive: This is where there is a combination of crests and troughs which makes the waves move higher and lower due to the interference.

Destructive: When one crest and one trough combine, the waves cancel each other out.

## Double Slit Interference

Definition: When the interference is created from one source, but has to go through the two openings, ultimately dividing into two waves.

## Differences of Dual Pin and Double Slit

Dual Pin creates two spherical waves, while Double Slit makes two almost semi circle waves. Both of these however have constructive and destructive interferences. Dual Pin does not have to pass a boundary before the waves are created. Double Slit has to pass the rods and travel through the slit before the waves are created.

## Wave Reflection 1, 2, and 3

Law of Reflection:

States that the incident ray, the reflected ray, and the normal to the surface of the mirror all lie in the same plane. Furthermore, the angle of reflection is equal to the angle of incidence.

## Wave Diffraction

Definition: Involves a change in direction of waves as they pass through an opening or around a barrier in their path.

## Initial Set Up

Observations of picture below: The waves only pass through the opening of the barriers. They have to become smaller to fit through but once they pass through they start to expand.

## Barrier Gap Changed

The barrier gap was made bigger so there was more space for the waves to pass through. There is a bigger space for waves in this picture than the one above.